ocamlopt debugging options

ocamlopt debugging options

[Alexey Rodriguez]

Dear List,

Sometimes it is useful to see what is the code produced by ocamlopt in
order to assess the performance of programming constructs. It is
possible to use -dcmm, but it is difficult to relate ocaml functions
to their compiled form due to the names used in the cmm dump. How do
you people get around that difficulty?

One more thing, are the ocamlopt undocumented options documented somewhere? :)

Cheers,

Alexey

Re: [Caml-list] ocamlopt debugging options

[Mark Shinwell]

On Thu, Apr 23, 2009 at 12:30:31PM +0200, Alexey Rodriguez wrote:
> Sometimes it is useful to see what is the code produced by ocamlopt in
> order to assess the performance of programming constructs. It is
> possible to use -dcmm, but it is difficult to relate ocaml functions
> to their compiled form due to the names used in the cmm dump. How do
> you people get around that difficulty?

I use objdump -Dr :)

Mark

Re: [Caml-list] ocamlopt debugging options

[Alexey Rodriguez]

On Thu, Apr 23, 2009 at 12:34 PM, Mark
Shinwell<mshinwell@janestcapital.com> wrote:

> I use objdump -Dr :)

Ok. It took me a long to reply to this, but better late than never.

I used objdump as you suggested and I do not mind reading assembler
but I have the same problem as with cmm, namely that symbolic names
are gone.

So, I repeat my question. How do you people do to relate labels in the
generated code with the ocaml function names in the source?

Thanks!

Alexey

Re: [Caml-list] ocamlopt debugging options

[Daniel Bünzli]

Le 18 juin 09 à 15:52, Alexey Rodriguez a écrit :

> I used objdump as you suggested and I do not mind reading assembler
> but I have the same problem as with cmm, namely that symbolic names
> are gone.

If you compile with -S they should not be gone in the generated  
assembly file. More explanations here :

http://ocaml-tutorial.org/performance_and_profiling

Best,

Daniel

Re: [Caml-list] ocamlopt debugging options

[Alexey Rodriguez]

2009/6/18 Daniel Bünzli <daniel.buenzli@erratique.ch>:

>
> If you compile with -S they should not be gone in the generated assembly
> file. More explanations here :
>
> http://ocaml-tutorial.org/performance_and_profiling

Thank you! It was my silly mistake after all. I was testing a small
program to see whether functions would be inlined. Ocaml did inline
them and that is why I did not see them! :)

One more question regarding code generation and optimization. Has
anyone in this list used monads in production code? The core library
from Jane Street uses monads, so I suppose they are used over there.
Can people comment on their efficiency (or lack thereof)?

The experiments I am doing are to test whether Ocaml can inline most
uses of bind.

Cheers,

Alexey

Re: [Caml-list] ocamlopt debugging options

[Mark Shinwell]

On Thu, Jun 18, 2009 at 03:52:46PM +0200, Alexey Rodriguez wrote:
> I used objdump as you suggested and I do not mind reading assembler
> but I have the same problem as with cmm, namely that symbolic names
> are gone.

Exactly what form of symbolic name are you referring to?  Function names
are preserved (although they are mangled, but it's a lot easier to
decipher than C++ mangling).

Mark

Re: [Caml-list] ocamlopt debugging options

[Alexey Rodriguez]

On Thu, Jun 18, 2009 at 4:10 PM, Mark
Shinwell<mshinwell@janestcapital.com> wrote:
>
> Exactly what form of symbolic name are you referring to?  Function names
> are preserved (although they are mangled, but it's a lot easier to
> decipher than C++ mangling).

You are absolutely right. I was my own mistake, see the other message. Thanks!

Cheers,

Alexey